Unilateral hyperreactio luteinalis of the ovary during pregnancy mimics ovarian malignancy: A case report

Hyperreactio luteinalis (HL) involving a unilateral ovary is extremely rare, and the clinical presentation of HL can mimic that of ovarian malignancy, resulting in potential misdiagnosis and unnecessary surgical interventions.

A 34-year-old female (gravida 6, para 1), pregnant for 6 weeks according to her menstrual records, presented with nausea and abdominal distension.

Ultrasonography revealed unilateral ovarian enlargement with multilocular cysts and ascites. Cancer antigen 125 (CA125) was elevated at 337.6 U/mL, raising suspicion of ovarian malignancy.

Surgery was performed due to the initial impression of malignancy. Intraoperative frozen section examination revealed multiple luteinized cysts, confirming HL.

The final diagnosis of HL was established, and unnecessary radical surgical procedures were avoided. The patient has followed up for >3 years, and there are no abnormalities in her serum CA125 and gynecological ultrasound results.

HL can mimic as ovarian malignancy, when encountering pregnant women with ovarian enlargement, elevated CA125 levels, and ascites, HL should be considered as a potential differential diagnosis. This awareness is crucial for accurate diagnosis and appropriate management, helping to avoid unnecessary surgical interventions.